Grain boundary self-diffusion of $^{57}$Co, $^{51}$Cr, $^{59}$Fe and $^{54}$Mn in a coarse-grained, single-phase fcc CoCrFeMnNi high entropy alloy is measured in a wide temperature range of 643 to 1273~K in both C- and B-type kinetic regimes after Harrison's classification. The results suggest that the product of the pertinent segregation factors, $s$, and the grain boundary width, $δ$, is about 0.5~nm for all elements at temperatures $T>800$~K. Whereas one short-circuit contribution is observed at higher temperatures above 800~K, the penetration profiles in the C-type kinetic regime (643 -- 703~K) reveal two distinct contributions that hint towards a phase decomposition at a fraction of high-angle grain boundaries at these temperatures. A correlative microscopy combining transmission Kikuchi diffraction and atom probe tomography manifests formation of neighbouring Ni-Mn-rich and Cr-rich precipitates at a segment of high angle grain boundaries. Transmission electron microscopy revealed an increased dislocation density in the vicinity of such interfaces which is suggested to be a reason of the enhanced diffusion rates at low temperatures for such short circuits.
Concentration-dependent atomic mobilities in FCC CoCrFeMnNi high-entropy alloys
本文用Co $_{15}$ Cr $_{20}$ Fe $_{20}$ Mn $_{20}$ Ni $_{25}$/Co $_{25}$ Cr $_{20}$ Fe $_{20}$ Mn $_{20}$ Ni $_{15}$对的放射性示踪-互扩散联合实验研究了CoCrFeMnNi高熵合金中的扩散动力学。结果，确定了Co，Cr，Fe和Mn的成分依赖的示踪剂扩散系数。元素的特征在于显著不同的扩散速率，Mn是最快的元素，Co是最慢的元素。发现通过扩散偶的等原子浓度的元素显示出上坡扩散，尤其是Cr和Mn。Co的原子迁移率沿扩散路径呈现S形浓度依赖关系，实验测得的动力学数据与现有的CALPHAD型数据库进行了比较。为了确保示踪剂和化学扩散的一致处理，提出了一种多组分互扩散的广义对称化连续介质方法。示踪剂和化学扩散浓度分布进行了模拟和比较的测量。通过使用测量的示踪剂扩散系数的化学配置文件可以描述，几乎完美，包括上山扩散。
An Active Learning Interatomic Potential For Defect-Engineered CoCrFeMnNi High-Entropy Alloy
University of Tokyo（东京大学）；Indian Institute of Technology Gandhinagar（甘地纳加尔印度理工学院）；Herbert Gleiter International Institute, Liaoning Academy of Materials（赫伯特·盖勒国际研究所，辽宁材料研究院）；Regional Institute of Education（地区教育学院）
Experimental and theoretical study of tracer diffusion in a series of (CoCrFeMn)$_{100-x}$Ni$_x$ alloys
本文研究了在不同温度下，从纯Ni到等原子CoCrFeMnNi高熵合金的一系列（CoCrFeMn）$_{100-x}$ Ni $_x$合金中所有组成元素的示踪扩散。在一个给定的同源温度下，测得的示踪剂扩散系数的变化非单调沿过渡从纯镍的集中合金，最后等原子的CoCrFeMnNi合金。这是解释原子蒙特卡罗模拟的基础上修改嵌入原子的潜力，它揭示了一个空位周围的原子配置的局部非均匀性引起的相关效应，并诱导显着偏离随机合金模型的预测。
Impact of interstitial carbon on local lattice distortions in CoCrFeMnNi high-entropy alloys
Helmholtz-Zentrum Berlin für Materialien und Energie (HZB)（柏林亥姆霍兹材料能源中心）；Institute of Solid State Physics, University of Latvia（拉脱维亚大学固体物理研究所）；Department of Metallurgical and Materials Engineering, Indian Institute of Technology Patna（巴特那印度理工学院冶金与材料工程系）；Deutsches Elektronen-Synchrotron DESY（德国电子同步辐射中心）；Interdisciplinary Centre for Advanced Materials Simulation, Ruhr-Universität Bochum（鲁尔大学波鸿跨学科先进材料模拟中心）；Department of Computational Materials Design, Max-Planck-Institute for Sustainable Materials（马普可持续材料研究所计算材料设计系）；Institute for Materials Science, University of Stuttgart（斯图加特大学材料科学研究所）；Institute of Materials Physics, University of Münster（明斯特大学材料物理研究所）
Edge Dislocation Mediated Anomalous Charge Transfer in Face Centered Cubic High Entropy Alloys
School of Materials Science and Technology, IIT-BHU（印度理工联合学院瓦拉纳西分校材料科学与技术学院）；National Centre for Computational Sciences, Oak Ridge National Laboratory（橡树岭国家实验室国家计算科学中心）；Department of Metallurgy and Materials Engineering, IIEST Shibpur（IIEST Shibpur冶金与材料工程系）
In-Situ TEM Observation of Solid-State Phase Evolution in High-Entropy Alloy Nanoparticles
University of Petroleum and Energy Studies (UPES)（石油与能源大学）；Indian Institute of Technology, Kharagpur（印度理工学院哈格普尔分校）；Brazilian Centre for Research in Energy and Materials（巴西能源与材料研究中心）；State University of Campinas（坎皮纳斯州立大学）；Rice University（莱斯大学）；Federal University of ABC (UFABC)（ABC联邦大学）；Michigan Technological University（密歇根理工大学）
